Electronic football linesman

ABSTRACT

An electronic system using RF Transmitters, Receivers, Transponders and a Computer are used to measure location and distance. Using a unique method, this system measures the delay between direct and echoed RF signals from different aspects to convert RF propagation delay into triangulated distance information. It is configured to act as a measuring tool for the linesman in the game of football. It is used to spot the ball (determine location), determine if a first down has been achieved (measure/calculate change in location) and aid the linesman in centering the ball on the playfield and assess penalties(give a constant location reading).  
     Unlike radio direction finding methods of locating a football, it has no moving parts and is completely cordless.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not Applicable

STATEMENT REGARDING FED.SPONSORED RESEARCH OR DEV.

[0002] Not Applicable REFERENCE TO A MICROFICHE APPENDIX

[0003] Not Applicable

BACKGROUND OF THE INVENTION

[0004] During many football games the playing field can become so tom-upthat determining distance and centering the ball correctly becomesimpossible. When there is a question of whether the yardage for a firstdown has been achieved, the game must stop and the chains are broughtout. An electronic system using a unique method of determining distanceand location is used to eliminate these problems.

BRIEF SUMMARY OF THE INVENTION

[0005] This is an electronic system using a unique method to locate theposition of the football on the playing field. It is comprised of RFtransmitters, and a receiver/microcomputer that measure the RFpropagation delay between direct and echoed signals to determine thefootball's location. Once the location of the ball is determined“spotted”, needed information can be calculated and displayed on thescoreboard such as: distance required for a first down, total yardage,etc. In addition, the system can give position information continuouslyto aid the operator while moving the ball from the sideline to thecenter of the field (across the field), or assess a penalty (up or downthe field).

BRIEF DESCRIPTION OF DRAWINGS

[0006] Drawing 1 is a System View.

[0007] Drawing 2 is The Wand.

[0008] Drawing 3 in The Repeater Unit.

[0009] Drawing 4 is the Master Receiver, Master Logic Unit and OptionalScoreboard. All Drawings are Pictorial Views. Exact dimensions andorientations are not critical to the gist of this application.

DETAILED DESCRIPTION OF THE INVENTION

[0010] An electronic system using RF and digital components areconfigured such that they act as a distance measuring device. A uniquemethod is used to measure the propagation delay of RF signals(electromagnetic waves) and derive distance. This is best understood byfirst describing the components of the system and then the method inwhich they are used.

[0011] The system is composed of four general parts: The Wand, theRepeaters, the Master Receiver and the Master Logic Unit.

[0012] 1) The Wand.

[0013] The Wand is portable and acts as the system controller (see FIG.1). The operator may control all functions of the system remotely fromit. It has a Control Panel where the operator may select the operationto be made, such as, spotting the ball. An internal Logic Unit encodesall transmissions into a digital format and adds a code telling thesystem what type of instruction is to follow. It communicates with therest of the system through a FM Modulated Digital Burst Transceiver. TheWand is equipped with a telescopic antenna that the operator can extendwhen marking the ball.

[0014] 2) The Repeaters

[0015] Each Repeater is comprised of a FM Digital Burst Transceiver andLogic Unit (see FIG. 4). When it receives a coded digital burst from thewand, it determines if it is a ball “spot” command. If so, it transmitsa coded burst to the Master Receiver. The system contains four Repeatersand they are located at the corners of the playfield. The RepeaterAntennas are covered with foam rubber and they double as playfieldcorner markers (see FIG. 3).

[0016] 3) The Master Receiver

[0017] The Master Receiver is made up of four dedicated FM receivers(only), each corresponding to a Repeater and tuned to its frequency.Also, there is a single transceiver for two-way communication with theWand. Its function is to receive commands and echo acknowledgements. TheMaster Logic Unit has total control of the Master Receiver.

[0018] 4) The Master Logic Unit

[0019] The Master Logic Unit is the “brains” of the system. It ismicrocomputer based and is equipped with a high frequency master clockit uses as a timer. The Master Logic Unit monitors the outputs from theMaster Receiver. When it receives the ball “spot” command originatingfrom the Wand, it begins to count and record the cycles from the masterclock until it receives the pulse from each of the Repeaters. It thendetermines location of the wand (held next to the ball) using amathematical algorithm. The Master Logic Unit also receives command dataoriginating from the Wand to control game clock, assess penalties, etc.The Master Receiver and Master Logic Unit are normally housed in thescoreboard, but can be housed in a standard computer chassis when thecustomer wishes to interface with an existing scoreboard.

DESCRIPTION OF USE

[0020] Set-Up

[0021] The repeaters are placed on the corners of the playfield. Theyare pressed into the ground with only the antenna showing. The antennais covered with plastic foam and doubles as a visual corner marker. Thescoreboard (optional) is mounted to portable rods that are pressed intothe ground.

[0022] Calibration

[0023] The system must have a base line from which to determinedistances. In other words, it must know where the “End Zones” are. TheMaster Logic Unit must know what the maximum and minimum signal delaysare between receipt of the Wand and Repeater Signals. The system isplaced in calibration mode. Then the operator goes to each corner of thefield and places the Wand next to the Repeater and presses the “spot”button activating the transmitter. The Master Logic Unit records theMaster Clock count with the Wand at its closes and farthest possiblepoints from each Repeater.

[0024] The Repeaters have an internal delay while switching from receiveand transmit, that will differ between units and could present an errorfactor. However, this delay is eliminated by this calibration methodbecause the mathematical algorithm subtracts the minimum delay frommaximum delay leaving only the time it takes for the RF signal topropagate across the field.

[0025] Operation

[0026] The operator (linesman/official) carries the Wand during thegame. Its primary function is to spot the ball. When the ball is downed,the operator marks its location by placing the Wand next to the nose ofthe ball and pressing the “spot” button. The Master Logic unitdetermines the location of the ball and updates the scoreboard.

[0027] In order to aid the operator in moving the ball from the sidelineback to the center of the field, the system has a continuous “ping”mode. Once the ball is spotted, the scoreboard gives the currentposition of the Wand in 1-second intervals. The operator walks to thecenter of the field and looks at a special display the scoreboard. TheWand is moved back and forth until the special display indicates theposition is the same as that when spotted. He places the nose of theball against to the wand and play resumes.

[0028] If the operator assesses a penalty, the Master Logic Unitadds/subtracts the penalty yardage, and the system goes into ping modedirecting him/her to the new line of scrimmage.

1) What I claim as my invention is a method of determining location anddistance on a football field by using a differential measurement of thepropagation delay of an electro-magnetic wave from a transmitter placednext to the ball. This method is described by the set-up, calibrationand operation steps as follows: a) Set-up the system by placing therepeater units at the corners of the playing field and the MasterReceiver/Master Logic Unit on the sidelines. b) Calibrate the system byplacing the transmitter Wand at one corner of the playing field andtransmitting an RF burst. Receiving the directly transmitted burst atthe Master Receiver/Logic Unit. Measuring the difference in time untilthe echoed burst from each of the Repeaters arrives at the MasterReceiver/Master Logic Unit. Repeating this differential measurement asthe Wand is moved to the other corners of the playing field. c) Usingthe measured maximum and minimum differential propagation delay,corresponding to farthest and nearest distance the Wand will be fromeach of the Repeaters, create a mathematical algorithm to translate thisdifferential propagation delay into positioning on the field in yards.d) Operating the system during the football game by placing the Wandnext to the ball and sending out an RF burst, which is then used todetermine the location of the football on the field. 2) Using the methodof determining the position of the football on the playing field asdescribed in claim 1, determine dynamic and statistical data about thegame including but not limited to: a) Yards to go for a first down b)Total offense yards c) Total yards of penalties 3) Using the method asdescribed in claim 1, send out a continuous stream of RF bursts from theWand to give constant position information of the Wand for the purposeof: a) Repositioning the ball on the playing field b) Assessingpenalties